The invention concerns a ventilator comprised of a one-part housing of plastic material with the integrated elements inlet nozzle, cylindrical flow guiding means, diffusor, outlet guide vanes, and a motor support connected thereto; an impeller wheel that is supported so as to rotate about a central axis and that is comprised of a central hub and vanes connected thereto with flow elements (winglets) at the radial outer ends; an electric drive motor that is embodied as external rotor motor either in AC or EC technology; as well as a protective screen that can be connected to an appropriate device of the housing provided for this purpose.
WO 2004/094835 A1 discloses a ventilator with a ventilator conveying passage and an impeller wheel arranged therein that is rotatable about a central axis and has a central hub with an outer circumference on which ventilator vanes are attached that extend with their radial outer edges up to a surface that provides an outward boundary and that have crescent-shaped leading edges and that, in the area of the radial outer edge, are provided with flow elements that are designed as flow obstacles for a compensation flow flowing about this radial outer edge from the pressure side to the suction side.
In the Fan Noise article “Experimental Aeroacoustic Analysis of Efficient Automotive Engine Cooling Fan System”, 2003, an energy-efficient ventilator for use in vehicle cooling systems is described that is comprised of an impeller wheel with motor mounted in a housing that integrates the functional elements cylindrical flow guiding means, diffusor, and outer guide vanes in one component, wherein the compact configuration of the ventilator is emphasized.
It is the object of the invention to provide a ventilator which, while having a compact configuration, provides further noise reduction as well as a higher degree of efficiency wherein a protective screen is also integrated into the inventive ventilator.